Feeding mechanism for sewing machines



Jun 1930. N. y. CHRISTENSEN ET AL 1,763,952

FEEDING-MECHANISM FOR SEWING- MACHINES E i Q i i} Q) I ,l .mfl' :11 Xi I 3 I l N J1me 1930- N. v. CHRISTENSEN ET Al. 1,763,952

FEEDING MECHANISM FOR SEWING MACHINES Filed March 12, 1926 3Sheets+Sheet 2 June 17, 1930. v, cHRlSTENSEN ET AL 1,763,952

FEEDING MECHANISM FOR SEWING MACHINES Filed March 12, 1926 3 Sheets-Sheet 3 Patented June 17, 1930 UNITED STATES PATENT OFFICE NORMAN V. CHRISTENSEN AND WALTER M. HANNEMAN, OF CHICAGO, ILLINOIS, AS- SIGNORS T UNION SPECIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS, A COR- PORATION OF ILLINOIS FEEDING MECHANISM FOR SEWING MACHINES Application filed March 12, 1926. Serial No. 94,250.

r vide a feeding mechanism of the above type,

wherein the feed bar is mounted on swinging links at both ends thereof, and wherein one of sa1d links is mounted on an eccentric pm which can be adjusted and locked in different adjusted positions for raising or lowering the path of movement of the feed dog, for tilting the feed dog or for leveling the same.

A further object of the invention is to provide a. sewing machine having a feeding mechanism of the above type, wherein a rock lever for moving the looper shaft endwise is mounted on an axis coincident with the rock lever for moving the feed bar back and forth.

A still further object of the invention is to provide a machine of the above type wherein the connection between the looper shaft and the rock lever is adjustable for L varying the amount of endwise movement imparted to the looper shaft.

Still another object of the invention is to provide a sewing machine having a feeding mechanism of the above type with thread carrying loopers and a stationary needle guard which cooperates with the needles in properly positioning the same for the loopcrs to pass.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings which show by way of illustration one embodiment of the invention Fig. l is a view partly in section and partly in front elevation showing a portion of a machine having the improvements embodied therein;

Fig. 2 is a plan view of the work supporting arm removed from the machine, the cover plate and end cap being also removed so that the operating parts within the arm are exposed to View;

Fig. 3 is a sectional view on the line 3-3 of Fig. 2; i

Fig. 4 is a sectional view on the line 44 of Fig. 2;

Fig. 5 is a perspective view of the swinging links and supporting pin for the rear end of the feed bar;

Fig. 6 is a sectional view on the line 6-6 of Fig. 1;

Fig. 7 is a perspective view of the needle guard;

Fig. 8 is a detail showing the means for supporting the crank on the main shaft, which crank oscillates the looper shaft;

Fig. 9 is a front view of the work supporting arm showing the removable cover plate which affords access to the actuated parts which transmit movement to the feed bar and the looper;

Fig. 10 is a view partly in side elevation and partly in section, showing the feed bar, the feed dog carried thereby, and a portion of the forward link which supports the front end of the feed bar;

Fig. 11 is a sectional view on the line 11, 11 of Fig. 1; p I

Fig. 12 is a longitudinal sectional view of the rear end of the work supporting arm,

and showing a modified form of rock lever for moving the looper back and forth, and- Fig. 13 is a sectional view on the line 18 of Fig. 12.

The invention is directed broadly to a feeding mechanism for a sewing machine having a suspended work supporting arm,

and preferably a machine of the type shown in the application filed by Messrs. Christensen & Le Vesconte, February 16, 1925, Serial No. 9584. The machine of the present application includes a supporting base or frame which is provided with an overhanging portion at. the upper end to which the main depending portion and. projects laterally.

therefrom, so that the material being stitched may be wrapped about said arm and fed off from the end thereof.

The improved feeding mechanism forming the subject-matter of this application consists of a feed dog 7 secured to a feed bar 8 by means of a screw 9. The feed bar 8 has a forked end 10 at the rear end thereof (see Fig. 10). The feed bar issupported at its rear end by a swinging link support 11. This swinging link support consists of a plate portion 11" and an arm portion 11 which are mounted on a sleeve 12. This sleeve 12 is mounted on a pin 13 which is provided with an eccentric portion 14. Said pin is also provided with a slotted head 15 which is accessible from the outer face of the work support ing arm, so-that the pin 15-may be turned or set in various positions for raising and lowering the swinging link support. A set screw 16 is used for securing this eccentric pin in various set positions. Mounted in theplate 11 and the arm '11 is a pin 17 which is slabbed to provide a reduced portion 18 of a thickness corresponding to the forked end 10, so that said forked end 10 of the feed bar will straddle said pin 17 and be supported thereby. This forked end of the feed bar moves freely back and forth on this pin, but it will be raised and lowered as the pin is raised and lowered. The only vertical movements imparted to the pin are those incident to the rocking of the swinging link support. The feed bar is mounted at its forward end on links 19 which are pivoted at 20 to the feed bar, and at 21 to a lever 22 which is fulcrumed on a.pin 23. This pin 23 is provided with an eccentric portion. The pin 23 is capable of being adjusted and held in adjusted positions by a set screw 24. This pin is also accessible from the outer faceof the work supporting arm, and when it is adjusted it will raise or lower the lever 22. The lever 22 projects rearwardly, and is bent upardly and provided with a spherical head 25 with which the lower end of an eccentric strap 26 cooperates. Said eccentric strap in turn cooperateswith an eccentric 27 on the main shaft 2. It is through this lever and the links 19 that the movement of the eccentric 27 imparts an up and down movement to the 3 feed dog.

The swinging link support 11 is provided with a. segmental slot 28. The link 29 is pivotally attached at 30 to the feed bar. The rear end of this link is connected to a stud 31 which is capable of being adjusted in the Said eccentric strap in turn cooperates with an eccentric 39 secured to the main shaft 2. Mounted on the sleeve and spaced from the headed portion 36, is a collar 40 which is provided with a depending arm 41. This de pending arm 41 is connected to a link 42 2 which in turn is pivoted at 43 to the swinging link support 11.

. As the main shaft rotates, the eccentric strap 38 will oscillate the rock frame, and through the arm 41 and link 42 will swing the link support 11 back and forth. The swinging movements of this link support through the link 29 will move the feed bar back and forth, thus imparting feeding movements to the feed dog.

The eccentric pins 13 and 23 can be adjusted and set in adjusted positions as has been noted above. When the pin 13 is properly turned, it will raise or'lower the swinginglink support 11, and this will raise or lower the rear end of the feed bar. When the pin 23 is shifted, it will raise or lower the front end of the feed bar. It will readily be noted that these adjustments may be made so as to raise or lower the path of travel of the feed dog. They may also be manipulated so as to tilt'the feed dog, if desired.

Then again, they may be manipulated so as to level the feed dog.

Extending lengthwise of the work sup- F porting arm 4 is a shaft 44 on which the thread carrying loopers 45, 45 are mounted.

Fixed to the shaft aretwo spaced collars 46,

46. Between these spaced collars is a free freely in said collar 47. Said collar 47 has an upwardly extending lug to which a link 48 is pivoted. The link 48 is inturn pivoted.- to an arm 49. This arm 49-is carried by a sleeve 50 which turns on the sleeve 35 and is f5.

located between the head portion 36 and the collar 40 secured thereto. The sleeve 50 is provided with an arm 51 carrying a ball stud 52 to which an eccentric strap 53 is connect- Cd. Said eccentric strap 53 cooperates with iii .collar 47, so that the shaft 44 can oscillate i1 The looper shaft is mounted'atits rear end in the bearing formed on the inner face of the work supporting arm l. Said looper shaft terminates just after passing through said bearing and is provided with a crank 56. The link 57 engages said crank 56 at its lower end, and engages a crank 58 at its upper end. This crank 58 is carried by a plate 59 which is-provided with segmental slots 60. Screws 61 passing through the segmental slots 60 secure the plate 59 to the eccentric 54. This eccentric 54 rigid on the main shaft, and as the main shaft rotates, the crank 58 through the link 57, will oscillate the looper shaft, and thus move the loopers into and out of the needle thread loops. By loosening the screws 61 and adjusting the plate 59, the timing of the loopers can be varied.

In Figures 12 and 13 there is shown a slightly modified form of means for imparting endwise movement to the looper shaft, which permits the throw imparted to the looper shaft to be varied. 'The depending arm 49 is divided so as to provide spaced arms 49 (see Fig. 13). These arms are provided with segmental slots 49. A pin 49 mounted in said segmental slots 49 and is capable of being adjusted in said slots toward and from the axis of the shaft 33. The link 48 is freely mounted on a sleeve 42 located between the arms 49, 49 and mounted on said pin 49. This permits the free movement of the link 48 and also allows the point of connection thereof with the arm 49 to be shifted so as to vary the lateral throw of the loopers.

Mounted at the front end of the work supporting arm is a stationary needle guard 72. The shank of this needle guard is provided with openings 63, 63 through which screws 6-ipass for rigidly securing the needle guard to the end of the work supporting arm a. Said needle guard projects outwardly from the supporting part to which it is connected, and is located directly be neath the path of movement of the loopers. Said needle guard has a beveled face 65 which adapted to cooperate with one of a the needles, and the bevel face (36 which is adapted to cooperate with the other needle. 'llae purpose of these guards is to prevent the needles from being deflected so as to be struck by the loopers as they move forward to engage the needle thread loops carried by the needles.

It. will be noted that the shaft 33 is mounted in the detachable work supporting arm. 'iherefore, the feeding mechanism and looper mechanism may be readily disconnected from the actuating parts therefor on the main shaft, and the work supporting arm removed with the feeding mechanism and the looper mechanism assembled therein as a unit.

ing movements, also the endwise movement of the auxiliary feed bar would be imparted thereto from the main feed bar.

lVhile we have shown the feeding mechanism as especially adapted for feeding off the end of a. work supporting arm, it will be understood from certain aspects of the invention that the feed dog may be arranged so as to feed on to the arm. In order to render the connections between the operating parts in the depending portion of the frame and the operated parts in the work supporting arm accessible, we have provided an opening in the work supporting arm indicated at 67. This opening is in the side face of the arm and is closed by a cover plate 68 having a clove-tailed. connection with the frame. A spring arm 69 carriesa pin 70 which is adapted to engage a recess 71 in the arm for holding the cover plate in closed position. i

It will be noted that the looper shaft tershaft is directly above the crank on the looper shaft, and therefore, no wabbling movements are developed in the link during the oscillations of the looper. p

It will be obvious that minor changes in the details of construction and the arrangement of the parts may be made without departing from the spirit of the invention as set forth in the appended claims.

Having thus described the invention, what we claim as new and desire to secure by Letters-Patent, is-

1. A sewing machine including in combination, a work supporting arm, a feed bar extendinglengthwise of said arm, a feetv dog carried thereby, a swinging link sup- -port, means carried thereby for slidingly supportingone end of the feed bar, devices for swinging said support, means for connecting said support to the feed bar whereby the swinging movements of said support inipart longitudinal movements to said feed bar, swinging links for supporting the other end of the feed bar, a lever on which said swinging links are mounted, means for oscillating said lever for raising and lowering the feed dog, a fulcrum pin having an eccentric member for supporting said swinging support, means for holding said pin in adjusted positions, a fulcrum pin having an eccentric member for supporting said lever,

. dog carried thereby, a swinging link and means for raising or lowering saidswinging link support.

3. A sewing machine including a main frame having a depending member open at its lower end, a work supporting Var-m connected to and closing the lower end of said depending member and projecting laterally therefrom, a feed bar extending lengthwise of said work supporting arm, a feed dog carried thereby, a swinging link support, means carried thereby for slidingly supporting one end of the feed bar, devices for swinging said support,,means for connecting said support to said feed bar, said devices for swinging said support including a rock frame mounted in said work supporting arm centrally beneath said depending member, a main shaft extending over said depending member, and devices carried thereby for operating said rock frame.

4. A sewing machine including in combination, a work supporting arm, a feed bar extending lengthwise of said arm, a feed support, a fulcrum pin for said swinging link support, said swinging link support including spaced members, a pin extending from one member to the other and engaging the end of the feed bar for slidingly supporting the same, means pivoted to said support for rocking the same, a link connecting said swinging support to the feed bar for imparting endwise movements thereto, an eccentric member carried by said fulcrum pin, and means for holding said pin in adjusted ositions whereb said swin in su )ort can be raised and lowered.

5. A sewing machine including a main frame having a depending member, a work supporting arm carried thereby and pro jecting laterally therefrom, a feed member extending lengthwise of said work support-- ing arm, a feed dog carried thereby, a swinging link support, meanscarried thereby for slidingly supporting one end of the feed bar,

a rock frame mounted in said work supporting arm, a link connecting said rock vices for raisingand lowering said feed bar.

6. A sewing machine including a main frame, a main shaft located therein, said frame having a depending member, a work supporting arm suspended by said depending member, a feed bar extending lengthwise of said arm, a feed dog carried thereby, a swinging support for slidingly supporting the rear end of the feed bar, a link connecting said swinging support to said feed bar for moving the same endwise, means for raising and lowering the end of the feed bar carrying the feed dog, a rock frame mounted to swing about an axis at right angles to the longitudinal axis of the work supporting arm, a link connecting said rock frame to said swingingsupport for oscillating the same, and an eccentrlc on the mam shaft for osclllatmg sald frame.

In testimony whereof, we aflix our signa-. 

